The present disclosure relates generally to integrated circuits and more particularly to a method of layout design associated with an integrated circuit device.
The process of manufacturing integrated circuits (ICs) include several stages, of which, the definition of a pattern associated with the circuit is of critical importance. The pattern may be generated during the design process, and in particular in a layout design. The pattern may then be fabricated on a substrate using photolithography processes. There is significant pressure on the semiconductor industry to enable smaller and smaller critical dimensions of integrated circuits. Several approaches have been taken to decrease the linewidths of an IC even beyond the critical dimension provided by present lithography equipment (e.g., stepper or scanners). One such approach includes a method of fabricating integrated circuits by forming a masking element that provides a pattern at half critical dimension of the photolithography tool used. However, as critical dimensions further decrease, such approaches face issues such as insufficient process margins. The insufficient process margins may provide for errors in the linewidths of features fabricated on a substrate. Examples of errors that may occur include overlay errors between photomasks including patterns used to form the devices.
Therefore, what is needed is an improved method of layout design for a semiconductor device.